Download Anatomy-and-Physiology-Chapter

Anatomy and Physiology Chapter
#3
3.1 Introduction


Cells vary considerable in size, shape,
and function.
The shape of cells in the body vary
based on their function.
3.2 Composite Cell



Because cells vary so greatly in size,
shape, content, and function, describing
a “typical” cell is impossible.
All of the structures described in the
composite cell can NOT be found in
every cell regardless of function.
The organelles are found in the
cytoplasm of the cell.
Cell Organelles
1.
2.
3.
4.
5.
6.
7.
8.
Cell Membrane
Cytoplasm
Endoplasmic
reticulum (ER)
Ribosomes
Golgi Apparatus
Mitochondria
Lysosomes
Peroxisomes
9.
10.
11.
12.
13.
14.
15.
16.
Microfilaments and
Mircotubules
Centrosomes
Cilia and flagella
Vesicles
Nucleus
Nuclear envelope
Nucleolus
Chromatin
Cell Membrane




Extremely thin and semipermeable.
The cell membrane contains many kinds of proteins,
each with a special function.
Function: The membrane allows some substances to
enter and leave the cell but not others, participates in
signal transduction, and helps cells adhere to other
cells. The membrane forms a boundary around the
cellular contents,, and the basic structure of the cell
membrane is a lipid-protein bilayer.
Structure: The basic framework of the cell membrane
consists of a (bilayer) double layer of phospholipid,
with fatty acid tails turned in.
Cell Memebrane


The Phosphate Head is HYDROPHILIC
meaning "WATER
LOVING". Because of its hydrophilic
nature, the head of a Phospholipid will
orient itself so that it is as close as
possible to water molecules.
The Lipid Tails are HYDROPHOBIC
meaning "WATER-FEARING", the
Hydrophobic tails will tend to orient
themselves away from water.
Cytoplasm


The cytoplasm consists of a clear liquid
called cytosol, a supportive
cytoskeleton, and networks of
membranes and organelles.
Cell activities occur mainly in the
cytoplasm, where nutrients are
received, processed, and used.
Endoplasmic Reticulum




ER is made up of membrane-bounded flatten
sacs and elongated canals. ER provides a
tubular transport system inside the cell.
Rough ER: Has ribosomes on its outer layer
What does it function in the synthesis and
transport of? PROTEIN
Smooth ER: No ribosomes. What does it
function in the transport of? LIPIDS
Vesicles that have a role in secretion are
formed by the ER.
Ribosomes



They are found in the cytoplasm and ER
They composed of Protein and RNA
molecules.
Function is protein synthesis.


Popeye is active because he eats spinach.
However, for Popeye's cells to be active, his
ribosomes help create proteins.
Golgi Apparatus




They are composed of about 6 flattened,
membranous sacs.
Function is to refine, package, and deliver
proteins synthesized on ribosomes, and it
packages the cells products.
Vesicles that have a role in secretion are
formed by the golgi apparatus (and ER).
Plays a central role in the transport of new
molecules from inside to outside the cell.
Mitochondria



Is the POWERHOUSE of the cell and
contain enzymes that catalyze reactions
that release energy from nutrients
needed for aerobic respiration.
Enzyme is a protein that catalyzes a
specific biochemical reaction.
Adenosine Triphosphate (ATP) energy.
Lysosomes


The "garbage disposals of the cell“
They contain powerful enzymes to
break up old cell components and
bacteria. Example white blood cells can
engulf bacteria to fight bacterial
infections.
Peroxisomes


Membranous sacs are abundant in liver
and kidney cells.
They contain enzymes that function in
the synthesis of bile acids, breakdown
of lipids, degradation of rare
biochemicals, and detoxification of
alcohol.
Microfilaments and
microtubules



Thin, threadlike processes within the
cytoplasm that function in various kinds of
cell movement and that serve as the
cytoskeleton of the cell.
Microfilaments, made of the protein actin,
cause various cellular movements.
Mictotubules, made of the globular protein
tubulin. Form “9+2” pattern.
Centrosome


is a structure made up of two hollow
cylinders called centrioles.
Function in cell reproduction.
Cilia and flagella





They are motile extensions from the
cell.
Cilia is short and move “to-and-fro”.
Cilia function is to move fluids.
Flagella are longer and move in an
undulating wavelike motion.
What is the only flagellated cell in the
body? SPERM
Vesicles



Or vacuoles are formed by part of the
cell membrane.
They contain some liquid or solid
material formerly outside the cell.
Golgi and ER also form vesicles.
Nucleus, nuclear envelope

Is bounded by a double-layered nuclear
membrane (nuclear envelope)
containing relatively large nuclear pores
that allow the passage of certain
substances.
Nucleolus



Is a small, dense body composed
mainly of RNA.
Has no surrounding membrane.
Ribosomes form in the nucleolus.
Chromatin

Consist of loosely coiled fibers of DNA
and protein called chromosomes.
3.3 Movements through cell
membranes

1.
2.
3.
4.
Passive
mechanisms do not
require energy.
Diffusion
Facilitated diffusion
Osmosis
Filtration

1.
2.
3.
Active mechanisms
require cell energy.
Active transport
Endocytosis
Exocytosis
Passive



Diffusion is the process by which
molecules or ions scatter or spread
spontaneously from high concentration
to low concentration.
Oxygen and carbon dioxide can diffuse
readily through the cell membrane.
Equilibrium is reached.
Passive


Substances that are not able to pass
through the lipid bilayer need the help
of membrane proteins to get across,
this is called facilitated diffusion.
Carrier molecules “revolving doors” are
used to carry large molecules (glucose)
across the membrane.
Passive




Osmosis is the diffusion of water.
Solutions with a higher osmotic
pressure than body fluids are called
hypertonic.
Solutions with a osmotic pressure equal
to body fluids are called isotonic.
Solutions with a lower osmotic pressure
than body fluids are called hypotonic.
Passive


When fluid is forced through a
membrane by hydrostatic or blood
pressure, the mechanism is called
filtration.
Edema excess tissue fluid.
Active


Active transport is a process that moves
particles through membranes from a
region of low concentration to high
concentration.
Equilibrium is never reached.
Active

1.
2.
3.
In endocytosis molecules that are too large to be
transported by other means are engulfed by portion
of the cell membrane and carried into the cell
surrounded by a vesicle.
Pinocytosis is a form in which cells engulf liquids.
Phagocytosis is a form in which the cell takes in
larger particles, such as a white blood cell engulfing
a bacterium.
Receptor-mediated is a form in which receptors bind
specific particles, and they are drawn into the cell.

The reverse to endocytosis is
exocytosis.
3.4 The Cell Cycle




The series of changes a cell undergoes from
the time it is formed until it reproduces is
called the cell cycle.
The cell cycle is highly regulated. Most cells
do not divide continually. Cells have a
maximum number of
times they can
divide because of built-in “clocks” called
telomeres on the tips of chromosomes.
Mitosis cell division to form new cells (body
cells).
Meiosis cell division that forms sex cells
(gametes).
Mitosis (IPMAT)
1.
2.
3.
4.
5.
Interphase
Prophase
Metaphase
Anaphase
Telophase
Mitosis


Interphase is a period of great metabolic
activity in which the cell grows and
synthesizes new molecules and organelles.
During the S phase of interphase, the DNA of
the cell is replicated in preparation for cell
division.
Prophase chromosomes and centrioles
become visible and the nuclear envelope and
the nucleolus disappear.



Metaphase the chromosomes line up in the
middle of the cell. Spindle fibers are
connected to the centromeres of each
chromosome.
Anaphase centromeres are pulled apart and
chromosomes move in opposite directions.
Telophase chromosomes change back into
chromatin. Nuclear envelope and nucleolus
re-form. Cell membrane pinches.

Cytokinesis is the division of cytoplasm.
Cell Death



Apoptosis is a form of cell death that is
actually a normal part of development,
sculpting organs from overgrown tissues.
In the fetus, apoptosis carves away webbing
between developing fingers and toes.
Apoptosis follows a sunburn it peels away
cells so damaged that they might otherwise
turn cancerous.
Cancer
Cancer cells spread to distant areas
(metastasize), display excessive
growth (hyperplasia), and exhibit
properties found in earlier stages
(de-differentiation).
Work Cited
Golgi apparatus image.
www.sirinet.net/~jgjohnso/cell.html
 Mitochondria man image.
www.mitochondria.us/pages/rebep_main.html
 Mitochondria image.
www.mitochondria.us/pages/rebep_main.html
 Cell image.
www.merck.com/media/mmhe2/figures/fg001_2.gif
 ER image. www.science.siu.edu/plantbiology/PLB117/JPEGs%20CD/0073.JPG
 Ribosome image.
//anthro.palomar.edu/biobasis/bio_5.htm

Cell membrane image.
www.bioeng.auckland.ac.nz/images/
 Popeye cartoon.
www.//vilenski.org/science/safari/cellstructure/ribo.html
 Lysosome image.
www.people.virginia.edu/~rjh9u/lysosome.html
 Cytoskeleton image.
www.beyondbooks.com/lif71/4f.asp
 Animated sheep. www.beyondbooks.com

Centrosome image.
www.faculty.tcc.cc.fl.us/scma/smithh/centrioles.jpg
 Cilia and Flagella image.
www.academic.brooklyn.cuny.edu/biology/bio4fv/pag
e/flagella-movement.html
 Nucleus image.
www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBook
CELL2.html
 Carrier Molecule image.
www.msad54.k12.me.us/MSAD54Pages/skow/CurrPr
ojects/Biology/CrazyCells/Transport/transport%20prot
eins.htm




Edema image. www.nucleusinc.com
Mitosis image 1st pg.
http://campus.queens.edu/faculty/jannr
/cells/mit%20pics/mitosis%20animal.jp
g
Mitosis image.
www.mun.ca/.../BIOL2060/CellBiol17/C
B17_19.html